Patent Documents 1 to 31 disclose various condensed heterocyclic compounds, however, they failed to disclose the condensed heterocyclic compounds of the present invention. Usefulness of the condensed heterocyclic compounds of the present invention as pesticides, especially, as insecticides, acaricides or parasiticides against internal or external parasites in or on a mammal, fish or bird is not disclosed at all, PRIOR ART DOCUMENTS